Novel Cyclic Dipeptide Dehydrogenase and Assay Method for Activity

The cell-free extract prepared from cells of an albonoursin-producing actinomycete Streptomyces sp. KO2388 was found to catalyze the dehydrogenation of cyclo (L-Phe-L-Leu) (CFL) to albonoursin. This is the first report for the dehydrogenation at the α,β-positions of amino acid residues. The simple method for determining the dehydrogenation activity was devised by measuring the increase in UV absorption of the reaction mixture at 317nm, λmax(ε25,400) of albonoursin, where CFL had no absorption. Phenazine methosulfate was the most active cofactor for the dehydrogenation among several hydrogen acceptors.アルボノルシン生産菌、Streptomyces sp. KO2388株の無細胞抽出液が、cyclo(L-Phe-L-Leu)からアルボノルシンへの脱水素反応を触媒することを明らかにした。アミノ酸残基のα,β-位での脱水素反応を酵素レベルで明らかにしたのはこの報告が初めてである。本反応の簡便な測定法として、基質cyclo(L-Phe-L-Leu)には認められない。アルボノルシンの特異的な317nmにおける紫外吸収の増加を測定する方法を考案した。本方法を用いて数種の水素受容体を試験したところ、フェナジンメトサルフェートが最も有効であると判った

Trans-complemented hepatitis C virus particles as a versatile tool for study of virus assembly and infection

AbstractIn this study, we compared the entry processes of trans-complemented hepatitis C virus particles (HCVtcp), cell culture-produced HCV (HCVcc) and HCV pseudoparticles (HCVpp). Anti-CD81 antibody reduced the entry of HCVtcp and HCVcc to almost background levels, and that of HCVpp by approximately 50%. Apolipoprotein E-dependent infection was observed with HCVtcp and HCVcc, but not with HCVpp, suggesting that the HCVtcp system is more relevant as a model of HCV infection than HCVpp. We improved the productivity of HCVtcp by introducing adapted mutations and by deleting sequences not required for replication from the subgenomic replicon construct. Furthermore, blind passage of the HCVtcp in packaging cells resulted in a novel mutation in the NS3 region, N1586D, which contributed to assembly of infectious virus. These results demonstrate that our plasmid-based system for efficient production of HCVtcp is beneficial for studying HCV life cycles, particularly in viral assembly and infection

Retention of Capsule Endoscopy at the Site of NSAIDs-induced Intestinal Ulcer ―Lessons to Learn―

A 77-year-old man with a history of non-steroidal anti-inflammatory drugs (NSAID) use was admitted to our hospital due to anemia and hypoalbuminemia. Radioisotope scintigraphy indicated protein loss from the small intestine. The patient underwent capsule endoscopy, which was later found to be retained in the ileum. Double-balloon endoscopy showed multiple strictures with ulcers in the small intestine. The capsule was found in proximal to one of the stenosis, and was removed by doubleballoon enteroscopy. Based on endoscopic findings, NSAID-induced enteritis was diagnosed. Although anemia and hypoalbuminemia improved after discontinuing NSAID, the patient developed ileus and underwent partial resection of the ileum. Multiple diaphragm-like strictures were present in the resected intestine. The current case highlights the importance of screening for intestinal strictures when NSAID ulcer is suspected

Optimization of Deep Sedation with Spontaneous Respiration for Therapeutic Endoscopy Combining Propofol and Bispectral Index Monitoring

Background/Aims. This study aimed to establish optimal propofol anesthesia for therapeutic endoscopy, which has not been established. Methodology. We retrospectively investigated data on 89 patients who underwent upper-GI endoscopic submucosal dissection or endoscopic mucosal resection under anesthesia with propofol. Examined doses of propofol were changed according to efficacy and/or adverse events and classified into 5 periods. A bispectral index (BIS) monitor was used at Period 5 to decrease the incidence of adverse events caused by oversedation. The initial dose of propofol was administered after bolus injection of pethidine hydrochloride (0.5 mg/kg), and 1.0 mL of propofol was added every minute until the patients fell asleep. Continuous and bolus infusion were performed to maintain sedation. When the patient moved or an adverse event occurred, the maintenance dose examined was increased or decreased by 5 mL/h regardless of body weight. Results. Dose combinations (introduction : maintenance) and patient numbers for each period were as follows: Period 1 (n=27), 0.5 mg/kg : 5 mg/kg/h; Period 2 (n=11), 0.33 mg/kg : 3.3 mg/kg/h; Period 3 (n=7), 0.5 mg/kg : 3.3 mg/kg/h; Period 4 (n=14), 0.5 mg/kg : 2.5 mg/kg/h; Period 5 (n=30), 0.5 mg/kg : 2.5 mg/kg/h, using BIS monitor. During Period 5, an adverse event occurred in 10.0% of patients, which was lower than that for Periods 1–4. Conclusions. Period 5 propofol anesthesia with BIS protocol could be safe and useful for therapeutic endoscopy under deep sedation with spontaneous respiration

Day Surgery ヒガエリ シュジュツ ノ ゲンジョウ

From May 1999, the Day Surgery for the operations of inguinal hernia, cholecystolithiasis and benign thyroid tumor were introduced in our department. Twenty nine patients (5 inguinal hernia repairs in children, 11 tension free inguinal hernia repairs in adults, 8 laparoscopic cholecystectomies, 3 extirpations of benign thyroid tumors, 1 extirpation of giant breast tumor, 1 extirpation of skin tumor in child) were attempted to put the Day Surgery into practice. 2 cases (one : inguinal hernia of child, another inguinal hernia of adult) were not successful because of postoperative complications like wound pain. The day surgery for 27 cases were successfully carried out. As the Day Surgery has benefits of cutting down on expenses, saving time and reducing mental fatigue, the feelings of satisfaction of all of these patients were remarkably high. The system of the Day Surgery was almost established in our department , so we actively would like to extend the kinds of operations suitable for the Day Surgery

Assessment of the Initial Diagnostic Accuracy of a Fragility Fracture of the Sacrum: A Study of 56 Patients

Study Design Retrospective study. Purpose To investigate the clinical manifestations of a fragility fracture of the sacrum (FFS) and the factors that may contribute to a misdiagnosis. Overview of Literature The number of patients diagnosed with FFS has increased because of extended life expectancy and osteoporosis. Patients with FFS may report nonspecific symptoms, such as back, buttock, groin, and/or leg pain, leading to a misdiagnosis and a delay in definitive diagnosis. Methods Fifty-six patients (13 males and 43 females) with an average age of 80.2±9.2 years admitted to the hospital for FFS between 2006 and 2021 were analyzed retrospectively. The following patient data were collected using medical records: pain regions, a history of trauma, initial diagnoses, and rates of fracture detection using radiography, computed tomography (CT), and magnetic resonance imaging (MRI). Results Forty-one patients presented with low back and/or buttock pain, nine presented with groin pain, and 17 presented with thigh or leg pain. There was no history of trauma in 18 patients (32%). At the initial visit, 27 patients (48%) were diagnosed with sacral or pelvic fragility fractures. In contrast, 29 patients (52%) were initially misdiagnosed with lumbar spine disease (23 patients), hip joint diseases (three patients), and buttock bruises (three patients). Fracture detection rates for FFS were 2% using radiography, 71% using CT, and 93% using MRI. FFS was diagnosed definitively using an MRI with a coronal short tau inversion recovery (STIR) sequence. Conclusions Some patients with FFS have leg pain with no history of trauma and are initially misdiagnosed as having lumbar spine disease, hip joint disease, or simple bruises. When these clinical symptoms are reported, we recommend considering FFS as one of the differential diagnoses and performing lumbar or pelvic MRIs, particularly coronal STIR images, to rule out FFS

Hepatitis C Virus Controls Interferon Production through PKR Activation

Hepatitis C virus is a poor inducer of interferon (IFN), although its structured viral RNA can bind the RNA helicase RIG-I, and activate the IFN-induction pathway. Low IFN induction has been attributed to HCV NS3/4A protease-mediated cleavage of the mitochondria-adapter MAVS. Here, we have investigated the early events of IFN induction upon HCV infection, using the cell-cultured HCV JFH1 strain and the new HCV-permissive hepatoma-derived Huh7.25.CD81 cell subclone. These cells depend on ectopic expression of the RIG-I ubiquitinating enzyme TRIM25 to induce IFN through the RIG-I/MAVS pathway. We observed induction of IFN during the first 12 hrs of HCV infection, after which a decline occurred which was more abrupt at the protein than at the RNA level, revealing a novel HCV-mediated control of IFN induction at the level of translation. The cellular protein kinase PKR is an important regulator of translation, through the phosphorylation of its substrate the eIF2α initiation factor. A comparison of the expression of luciferase placed under the control of an eIF2α-dependent (IRESEMCV) or independent (IRESHCV) RNA showed a specific HCV-mediated inhibition of eIF2α-dependent translation. We demonstrated that HCV infection triggers the phosphorylation of both PKR and eIF2α at 12 and 15 hrs post-infection. PKR silencing, as well as treatment with PKR pharmacological inhibitors, restored IFN induction in JFH1-infected cells, at least until 18 hrs post-infection, at which time a decrease in IFN expression could be attributed to NS3/4A-mediated MAVS cleavage. Importantly, both PKR silencing and PKR inhibitors led to inhibition of HCV yields in cells that express functional RIG-I/MAVS. In conclusion, here we provide the first evidence that HCV uses PKR to restrain its ability to induce IFN through the RIG-I/MAVS pathway. This opens up new possibilities to assay PKR chemical inhibitors for their potential to boost innate immunity in HCV infection